# Engine error on start up

**URL:** <https://discourse.stonehearth.net/t/engine-error-on-start-up/21595>\
**Category:** Previous Build Reports\
**Created:** [April 19, 2016, 3:10pm UTC](https://discourse.stonehearth.net/t/engine-error-on-start-up/21595 "2016-04-19T15:10:32Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Corban\_Baltazar](https://avatars.discourse-cdn.com/v4/letter/c/96bed5/32.png) [@Corban\_Baltazar](https://discourse.stonehearth.net/u/Corban_Baltazar)\
**Post date:** [April 19, 2016, 3:10pm UTC](https://discourse.stonehearth.net/t/engine-error-on-start-up/21595/1 "2016-04-19T15:10:32Z")

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**Summary:**

**Steps to reproduce:**

1. Occurred on load up. Unable to reproduce at this stage.
2. 
3. 

**Expected Results:**  
Normal start up.  
**Actual Results:**  
Error report on start up each time game is loaded.  
**Notes:**  
Noticed some unusual activity previous gaming session in that while creating a “building plan” it became increasingly difficult to control viewing and block placement, also unable to delete objects while in “design building” mode.  
Mining left unmined, had to cancel and re set area to be mined

**Attachments:**  
**_Below is as copied from error report_** \*

release-549 (x64)  
…ehearth/renderers/fabricator/fabricator\_renderer.lua:23: assertion failed!  
stack traceback:  
[C]: ?  
[C]: in function ‘assert’  
…ehearth/renderers/fabricator/fabricator\_renderer.lua:23: in function \<…ehearth/renderers/fabricator/fabricator\_renderer.lua:13\>  
release-549 (x64)  
c++ exception: lua runtime error  
stack traceback:  
release-549 (x64)  
…ices/client/renderer/construction\_render\_tracker.lua:20: attempt to index field ‘\_bp’ (a nil value)  
stack traceback:  
[C]: ?  
…ices/client/renderer/construction\_render\_tracker.lua:20: in function '\_\_user\_init’  
radiant/lib/unclasslib.lua:270: in function '\_\_init’  
radiant/lib/unclasslib.lua:201: in function ‘ConstructionRenderTracker’  
…ers/construction\_data/construction\_data\_renderer.lua:23: in function \<…ers/construction\_data/construction\_data\_renderer.lua:11\>

**Version Number and Mods in use:**  
As per attached error report. No Mods  
**System Information:**  
WIN7 OS  
AMD A10-6800K APU with Radeon HD 4.10GHz. 8Gb RAM 64 bit OS

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**Author:** ![Relyss](https://sea2.discourse-cdn.com/flex022/user_avatar/discourse.stonehearth.net/relyss/32/41785_2.png) [@Relyss](https://discourse.stonehearth.net/u/Relyss)\
**Post date:** [April 20, 2016, 9:00pm UTC](https://discourse.stonehearth.net/t/engine-error-on-start-up/21595/2 "2016-04-20T21:00:29Z")

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Hey, @Corban_Baltazar, welcome to the forum! 😄  
Thanks for reporting 🙂